Low Profile Insect-Proof Closure for an Encasement

ABSTRACT

A low-profile insect-proof closure is provided for an encasement of insect-impervious fabric. A zipper is provided for closing an opening in the encasement. The zipper is stitched to the encasement and has a zipper head, and a zipper track on a fabric zipper belt. A fabric backing panel is stitched to the encasement behind the zipper at a closure zone of the zipper. A finger-shaped insert is provided attached to the fabric backing panel. The insert, which is made of compressible elastomer, is arranged so as to physically block or apply pressure to the zipper head to keep the zipper head in closed position when the encasement is on the mattress. The insert has a width no greater than the width of the zipper belt and a thickness less than about 10 millimeters.

FIELD OF THE INVENTION

The invention relates to encasements and more particularly relates toinsect-proof closures for encasements.

BACKGROUND OF THE INVENTION

Zippered fabric encasements are used to keep insects out of and awayfrom furniture, mattresses, pillows and supports, luggage and a host ofother articles. An encasement is essentially a sewn fabric bag thatcompletely surrounds or “encases” an article. It is typically designedto be close-fitting with the article it surrounds, but this is notalways the case. For example, an encasement for a bed may surround thebed and may provide a tent-like structure above the mattress to keepflying insects away from sleepers.

Insects are a nuisance and potential health hazard to humans and animals(e.g. mosquitoes, spiders, bedbugs). Insects may also be destructive toproperty (e.g. moths) and generally interfere with enjoyment of one'shome and possessions.

An encasement surrounds an article to prevent insects from entering andreproducing in/on the article. However, the weak point of an encasementis generally the zippered opening that allows the encasement to bepositioned on the article. Although the zipper may be zipped closed toclose the opening, a tiny gap at the final leg of the closure willgenerally remain (where the zipper head meets the end of the zippertracks). This tiny gap is frequently sufficient to allow passage of asingle insect (e.g. an adult bedbug is only 1.5-3 mm wide). From asingle insect intruder, a colony can quickly become established and thewhole point of the encasement ruined.

Further, the tiny gap in the closed zipper can easily and involuntarilybecome widened. Unrestrained, zippers can slip down with frictionalcontact. For example, on an encasement for a mattress, this can happendue to users' sleeping patterns, changing top bedding (such as fittedsheets), or from brushing past the zipper on the side of the mattress.

It would be desirable to provide a method of locking the zipper closed,while blocking the tiny gap to prevent insects from entering theencasement. However, bulky solutions are not desirable. Encasements aregenerally close-fitted to the encased article. Complicated flap closuresor thick quilted zones at the zipper closure are not desirable, as theydiminish the sleek appearance of the encasement, impede the intendedfunction of the zipper (by snagging, e.g.), and draw undue attention tothe insect-preventive aspects of the cover.

SUMMARY OF THE INVENTION

A low-profile insect-proof closure is provided for a encasement ofinsect-impervious fabric. A zipper is provided for closing an opening inthe encasement. The zipper is stitched to the encasement and has azipper head, and a zipper track on a fabric zipper belt. A fabricbacking panel is stitched to the encasement behind the zipper at aclosure zone of the zipper. A finger-shaped insert is provided attachedto the fabric backing panel. The insert, which is made of compressibleelastomer, is arranged so as to physically block or apply pressure tothe zipper head to keep the zipper head in closed position when theencasement is positioned on an article. The insert has a width nogreater than the width of the zipper belt and a thickness less thanapproximately 10 millimeters.

Various elastomeric materials are possible for the insert. One preferredmaterial is thermoplastic rubber (TPR) (or thermoplastic elastomer(TPE)), both of which have desirable compressibility and long wear.

The zipper head may have a cord loop that is attachable to a button onthe encasement to retain the zipper head in closed position. The cordloop may be of an elastic cord, such that the loop stretches to fitsnugly over the button.

Various shapes of inserts are possible. Preferably, the insert has asloped approach. The insert may have a textured or ridged upper surface.The insert may have at least one rounded edge. The insert may have adomed cross-section.

Preferably, the insert has a width less than approximately 20millimeters. Preferably, the insert has a length less than approximately10 centimeters.

Preferably, the insert has a non-snag surface.

Preferably, the insert is sized to fit between seams on the zipper belt.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a front view of the closure (zipper closed and locked).

FIG. 2 is a front perspective view of a encasement with zipper closedand locked.

FIG. 3A is a cross-section along line A-A of FIG. 3B.

FIG. 3B is a front view of the zipper closure (closed and locked).

FIG. 3C is a side view of the zipper closure of FIG. 3B.

FIG. 4 is a front view of the closure (zipper open and unlocked).

FIG. 5 is a front perspective view of a encasement with zipper open andunlocked.

FIG. 6A is a cross-section along line A-A of FIG. 6B.

FIG. 6B is a front view of the zipper closure (open and unlocked).

FIG. 6C is a side view of FIG. 6B.

FIG. 7A is a sectional view as zipper starts to close (showing slightcompression of insert projection).

FIG. 7B is a front view as zipper starts to close.

FIG. 8A is a front view of the insert.

FIG. 8B is a side view of FIG. 8A.

FIG. 8C is a bottom view of FIG. 8A.

FIG. 8D is an end view of FIG. 8A.

FIG. 9 is a sectional view of an alternative embodiment.

DETAILED DESCRIPTION

An encasement 200 is a fabric covering that surrounds an article on allsides to provide protection from insects. The encasement in this case ispreferably made of an insect-impervious material, or any fabric having asufficiently tight weave to prevent ingress of insects through thefabric. The encasement has a zippered opening. This may be disposed, forexample, along one long side and one short end of the encasement (forease of installation), or in some other configuration.

The zipper of the zippered opening is used to close the opening. Thismay be any type of zipper. However, fine-gauge zippers gauge arepreferred, as the size and frequency of the teeth does not permitpassage of insects between the closed teeth. As is known in the field ofzippers, the zipper is formed of a fabric belt 150 having two portions150A, 150B. Along corresponding edges of the fabric belt, correspondingmateable toothed tracks 130A, 130B are provided. These toothed tracks130 are joinable by means of a sliding zipper head 190, having agraspable zipper pull 120.

The zipper is stitched to the encasement along seams 160A, 160B at ornear the two edges of the zipper belt (generally opposite the toothedtracks). A terminal seam 140 is also provided where the end of thezipper meets the non-zippered body of the encasement. This seam isclearly shown in FIGS. 1 and 2.

The closure zone 100 of the encasement is of particular interest for thepresent invention.

The preferred embodiment of the invention provides two means ofreversibly “locking” the zipper closed in this zone. First, as shown inFIGS. 1-7B, a button and loop lock is provided to keep the zipper headat the end of its tracks, near seam 140. According to one embodiment,the loop 170 is an elastic cord that is attached (e.g. by being tied oritself over-looped) to an eye 125 of the zipper pull 120. The userstretches this elastic loop over button 180 (sewn to the encasement viathreads 220 just beyond the terminal seam 140), so that the loop is tautover the button, thus retaining the zipper head 190 in its most closedposition.

Second, and less visibly, a closure insert 210 is provided that helpsthe zipper to resist slippage and closes the tiny gap that exists in anycase between the zipper head 190 and the terminal seam 140. The insert210 is best seen on its own in FIGS. 8A-8D, but is also shown in sideand sectional views FIGS. 3A, 3C, 6A, 6C and 7A.

The insert is preferably made of a compressible elastomer. Oneparticularly preferred material is thermoplastic rubber (orthermoplastic elastomer). However, other materials are also possible.The material should have a dense texture, but be easily compressible bythe user, with a quick spring back to firmly press and retain the zipperhead in its most closed position.

The material should also permit machine washing and drying (i.e. a highwater and heat resistance).

The encasement has a fabric backing panel sewn to the encasement belowthe zipper in the closure zone. The insert may be sewn, fused oradhesively attached to this fabric backing panel. For example, theinsert may have a finger-shaped projection (as shown in FIGS. 8A-8D)that is disposed on a base platform 270. The base platform may beintegral with the projection or be a separate piece. The base platform270 may have stitching channels 290, 280 to allow it to be stitchedsecurely onto the backing panel.

Various shapes of the insert are possible. The projection of the insertmay be preferably rounded (and domed across the width of theprojection). A smooth (relatively flat) top surface (plateau) 240 ispossible (where the zipper head is retained in the most closedorientation), or the top surface may be ridged or textured (not shown)to provide additional gripping areas. Importantly, the insert isnon-textile in nature so it does not have fibres that can snag or becomeentrained in the zipper head or teeth in use. The projection may have amore blunt shaped bullnose (near the terminal seam 140) and a moretapered ramp 230 where the zipper approaches the insert. A very simpleinsert might have no separate base platform, and be simply adhered orfused to the backing panel.

The position of the insert is preferably at the terminal end of thezipper tracks. The projection of the insert is narrow enough to sitbetween the sewn edges of the zipper belt. It has a low profile. As canbe seen from the closed zipper views in FIGS. 1 and 2, the insert isalmost undetectable below the closed zipper, appearing as only aslightly raised or sloped area near the zipper head.

The dimensions of the insert are preferably in the range of about 0.2 to2 cm wide; about 1 to 10 cm long, and about 0.2 to 1 cm thick.

The interrelationship of the zipper and the insert is best seen in FIGS.3A, 6A and 7A. As seen in FIG. 6A, with the zipper open, the insert isin its relaxed state (at full expansion). When the zipper starts toclose, the insert becomes compressed by the zipper head 190 and theclosed zipper teeth behind the zipper head 130. The difference betweenthe compressed zone 250 and non-compressed zone 260 can be seen in FIG.7A. As seen in FIG. 3A, with the zipper fully closed, the insert 210 isfully compressed. The insert tries to expand but has nowhere to go (dueto the closed zipper tracks). The insert presses against the zipper head190 in this closed position to keep it from slipping back into openposition. The insert also blocks any possible gap in front of the zipperhead because the bullnose front end 310 of the insert 210 will cover thegap (which is minimized in any event due to the zipper pull being lockedwith the locking loop/button arrangement). Thus, insects are preventedfrom entering the encasement through the end of the zipper in theclosure zone 100.

The zipper may also be disposed so that the zipper head can be zippedbeyond the insert, as in the embodiment shown in FIG. 9. In thisarrangement, the edge 310 of the insert 210 physically blocks the zipperhead from sliding (or being slid) directly backward. In order to unzipthe zipper to open the encasement, the zipper head 190 must be liftedaway from the insert (i.e. by pulling on the zipper pull 120) to releasethe zipper head 190 from the insert edge 310. This “lift and release”catch adds a further measure of security to the closure arrangement.

The foregoing description illustrates only certain preferred embodimentsof the invention. The invention is not limited to the foregoingexamples. That is, persons skilled in the art will appreciate andunderstand that modifications and variations are, or will be, possibleto utilize and carry out the teaching of the invention described herein.Accordingly, all suitable modifications, variations and equivalents maybe resorted to, and such modifications, variations and equivalents areintended to fall within the scope of the invention as described andwithin the scope of the claims. A broad purposive construction of theclaim elements is intended. For example, one modification would be toomit the button/loop lock. Further, although a unitary insert is shown,it is also contemplated that several compressible dots or ridges orbuttons of compressible material could be provided to serve a similarpurpose (provided that a sufficiently insect-proof overall closure isprovided).

1. A low-profile insect-proof closure for an encasement ofinsect-impervious fabric, the closure comprising: a zipper for closingan opening in the encasement, the zipper being stitched to theencasement and having a zipper head, and a zipper track on a fabriczipper belt, the zipper having a terminal end where the zipper track isapproximately fully closed by the zipper head; a fabric backing panelstitched to the encasement behind the zipper within a closure zonesurrounding the terminal end; and a finger-shaped insert made ofcompressible elastomer attached to the fabric backing panel and arrangedwithin the closure zone but spaced away from the terminal end, such thatthe zipper head can be zipped to a position beyond the insert, whereinthe insert acts to physically block the zipper head to keep the zipperhead in closed position at the terminal end when the encasement ispositioned on an article; the insert having a width no greater than thewidth of the zipper belt and a thickness less than about 10 millimeters.2. The closure of claim 1, wherein the elastomer is thermoplasticrubber.
 3. The closure of claim 1, wherein the insert has a slopedapproach.
 4. The closure of claim 1, wherein the insert has a texturedor ridged upper surface.
 5. The closure of claim 1, wherein the inserthas a non-snag surface.
 6. The closure of claim 1, wherein the inserthas at least one rounded edge.
 7. The closure of claim 1, wherein theinsert has a domed cross-section.
 8. The closure of claim 1, wherein theinsert has a width less than about 20 millimeters.
 9. The closure ofclaim 1, wherein the insert has a length less than about 10 centimeters.10. The closure of claim 1, wherein the insert is sized to fit betweenseams on the zipper belt.
 11. The closure of claim 1, wherein the zipperhead has a cord loop, and the encasement has a button behind a stitchline of the closure zone, the loop attachable to the button to retainthe zipper head in closed position.
 12. The closure of claim 11, whereinthe cord loop is of an elastic cord, the loop being sized to stretch tofit over the button for secure closure.